It would be interesting to have next to each card, at least the one released in the last two to three years, the average percent the card is better than the pervious one and then the average percent price Difference.
So seeing as though this list is from best to worst reguardless of the actual difference in performence the best card would still be at the top, but lets use the GTX 280 as an example the entry (Using toms hardware charts: Performance Recap - Tom's Hardware : Nvidia GeForce GTX 260/280 Review
) Using the smaller moniter reference graph..
The Entry would look something like this.
GTX 280 [Performance: 4.09% Price: +45.88%]
So one could look at this and see, oh,ok, the GTX 280 is on average (Through all tests) about 4 % better than a GX2, however, costs an average of (at least using the two cheapest models of both cards from newegg) 46% more than a GX2.
So a GTX280 is better, but at costs a whole heck of alot more.
Could be done for all graphic Cards that we have averaged graphs for..
Sure it would be alot of work, and we would have to use the average price per cards based one one or two websites and we would also have to use graphs in which all the games and settings where averaged together like the example I showed.
But it would be well worth it as one list would tell anyone at a glance, the best card is, the difference in price compared to the one right below it and the difference in performance compared to the card below it.